AlexFN/publisher

[READ ONLY] The Publisher part of the RabbitEvents library (https://github.com/nuwber/rabbitevents)

RabbitEvents Publisher

The RabbitEvents Publisher component provides an API to publish events across the application structure. More information is available in the Nuwber's RabbitEvents documentation.

The RabbitEvents Publisher is the part that lets all other microservices know that a payment succeeded.

Table of contents

1. Installation via Composer
2. Configuration
3. Publishing
4. Testing

Installation via Composer

RabbitEvents Publisher may be installed via the Composer package manager:

composer require rabbitevents/publisher

After installing Publisher, you may execute the rabbitevents:install Artisan command, which will install the RabbitEvents configuration file into your application:

php artisan rabbitevents:install

Configuration

Details about the configuration are described in the library documentation.

Publishing

By using an Event class

This is an example event class:

<?php

use App\Payment;
use App\User;
use RabbitEvents\Publisher\ShouldPublish;
use RabbitEvents\Publisher\Support\Publishable;

class PaymentSucceededRabbitEvent implements ShouldPublish
{
    use Publishable;

    public function __construct(private User $user, private Payment $payment)
    {
    }

    public function publishEventKey(): string
    {
        return 'payment.succeeded';
    }

    public function toPublish(): mixed
    {
        return [
            'user' => $this->user->toArray(),
            'payment' => $this->payment->toArray(),
        ];
    }
}

The only requirement for event classes is to implement the \RabbitEvents\Publisher\ShouldPublish interface.

As an alternative, you could extend \RabbitEvents\Publisher\Support\AbstractPublishableEvent. This class was made just to simplify event classes creation.

To publish this event you just need to call the publish method of the event class and pass here all necessary data.

<?php

$payment = new Payment(...);

...

PaymentSucceededRabbitEvent::publish($request->user(), $payment);

The method publish is provided by the trait Publishable.

By using the publish function

Sometimes easier is to use the helper function publish with an event key and payload.

<?php

publish(
	'payment.succeeded', 
	[
	    'user' => $request->user()->toArray(),
	    'payment' => $payment->toArray(),
	]
);

Publish an Event object with the publish function

You also could use the combination of two previous methods.

<?php
$event = new PaymentSucceededEvent($request->user(), $payment);

event($event)
publish($event);

Testing

We always write tests. Tests in our applications contain many mocks and fakes to test how events are published.

There is the PublishableEventTesting trait that provides assertion methods in an Event class that you want to test.

Event.php

<?php

namespace App\BroadcastEvents;

use Nuwber\Events\Event\Publishable;
use Nuwber\Events\Event\ShouldPublish;
use Nuwber\Events\Event\Testing\PublishableEventTesting;

class Event implements ShouldPublish
{
    use Publishable;
    use PublishableEventTesting;

    public function __construct(private array $payload) 
    {
    }

    public function publishEventKey(): string
    {
        return 'something.happened';
    }

    public function toPublish(): array
    {
        return $this->payload;
    }
}

Test.php

<?php

use \App\RabbitEvents\Event;
use \App\RabbitEvents\AnotherEvent;

Event::fake();

$payload = [
    'key1' => 'value1',
    'key2' => 'value2',
];

Event::publish($payload);

Event::assertPublished('something.happened', $payload);

AnotherEvent::assertNotPublished();

If assertion does not passes Mockery\Exception\InvalidCountException will be thrown. Don't forget to call \Mockery::close() in tearDown or similar methods of your tests.